What was found
DURING CLIMB THROUGH APPROX FL300, LEVEL 3 CABIN ALTITUDE ALERT APPEARED. CONDUCTED EMERGENCY DESCENT PROCEDURE AS PER QRH & LEVELED OFF AT 10,000FT, CABIN ALTITUDE NEVER EXCEEDED APPROX 10,500FT ALTHOUGH CABIN RATE ALERT APPEARED SEVERAL TIMES DURING DESCENT. REPLACED CABIN PRESSURE CONTROL PANEL, REF AMM 21-31-03. OPS CHECK GOOD. REMOVED AND REPLACED CABIN AIR OUTFLOW VALVE ACTUATOR AS PRECAUTIONARY, REF AMM 21-31, OPS CHECK GOOD.